KENTON-ON-SEA, South Africa -- Lions are believed to have fatally mauled a group of poachers on a South African game reserve, according to the reserve's owner.

Sibuya Game Reserve owner Nick Fox said in a statement that anti-poaching dogs alerted reserve staff that "something was amiss" in the early morning hours of July 2. Staff members heard a commotion coming from the area where lions are kept and, suspecting that the lions' activity had disturbed the dog, did not immediately investigate further.

"It is not unusual to hear them at night. However, it now appears likely that the dog had been alerted by something else out of the ordinary coming from the lions," Fox wrote.

The next morning, warden guides found at least three sets of human remains near a high-powered rifle, gloves, wire cutters and survival equipment, tools generally associated with rhinoceros poaching activity.

"Clearly, the poachers had walked into a pride of six lions and some, if not all, had been killed," Fox said.

Fox said the reserve is arranging to tranquilize the pride of lions so that police forensic teams can investigate the deaths. It's possible that more than three poachers were killed, he added.

More than 1,000 rhinoceros were killed illegally in South Africa last year, according to statistics released earlier this year by the South African government. The country is home to the majority of the world's rapidly declining rhinoceros population, and conservationists warn that the rate at which the animals are being hunted is unsustainable, according to National Geographic.

Rhinoceroses are valued for their horns, which are falsely thought to have medicinal and aphrodisiacal properties in some cultures and are also used to create works of art.